1. Field of the Invention
The invention relates to a method for determining the contents of a fuel rod within a test range extending along the length of the fuel rod. The objective in particular is to distinguish fuel pellets of pure uranium dioxide from those which are doped with oxides of rare earths, for instance, with gadolinium oxide, Gd.sub.2 O.sub.3.
2. Description of the Prior Art
Heretofore, for this purpose, the closed fuel rod has been irradiated with a neutron source and subsequently, the secondary radiation of the fuel rod was recorded over its length. This secondary radiation of differently doped fuel pellets can be distinguished from the radiation of pure UO.sub.2 in the fuel rod. However, this so-called "rod scanning" requires considerable equipment in the form of a large number of measuring devices and radiation protection measures which represent a substantial investment.